Hey folks... it's been a very long time since I've posted in any meaningful way here, but I want to work on some ArcBuilder worlds again, and I decided that the best chance for good feedback would come from the users of this group. Since those who really contribute the hard numbers on my ArcBuilder mailing list are also members of this forum, I figured I can only improve my output by doing this.

So... here's the first project. The star in question is Gliese 33. Some of the more important stats that I have found are as follows:

Spectral type - K2V

Visual Luminosity - 0.245

Diameter - 0.882

Visual Luminosity HZ - 0.495 AU

Metallicity - 0.51

Mass - 0.83

Temp. - 4550 K

Age - 5.4 billion years

A planetary companion was inferred in 1999, out at 4.29 Au and with an eccentricity of 0, but as it remains unconfirmed at this late date, I'm discarding the possibility for now.

the main planet of interest is named Tsalos, a terrestrial body locked in a mutual orbit with another, nearly equal-sized terrestrial. As a quick note, I should mention that this double planet system is NOT natural, and that it was established for unknown reasons some 400 million years ago. I won't get into the details here, but this is a necessary fact for the system. Here are the orbital elements for the twins:

Distance from Stellar Primary - 0.478 AU

Orbital Eccentricity - 0.375

Orbital Period - 132.63 days

For those of you who are on my ArcBuilder mailing list, I'm using the default values. in my infinite wisdom, I purged all the email data I had received, and Yahoo! Groups browse function is currently being a bastard. So I figured it would be a simple matter to refine things once again. Okay, so, here is the data for the main world of interest, Tsalos:

Diameter - 11,950.8 km

Density - 5.47 gm/c3

Mass - 0.819

Surface Gravity - 0.93

Rotation Rate - 1,448.2 hours (tidally locked)

Atmospheric Pressure - 0.807

So, some basic facts about Tsalos. It was likely terraformed after it and its companion were placed in orbit about one another, and due to specifics of the story setting, that initial climate would have been largely tropical to subtropical. In fact, it is distinctly likely that the atmospheric pressure would have been greater than the Earth's, but only IF there is a plausible mechanism for its reduction in the intervening 400 million years to its current value. its companion (and currently unnamed) world would need to have initially been at a distance were tidal stresses would not caused major problems with Tsalos or its geology. I'm not certain what that distance is, however. I had numbers in an email, but, well, yeah....

I certainly do not have any problem with the CURRENT set up of the world having degraded from optimum values, even up to the point where the biosphere has become seriously compromised. So if anyone thinks that these values need to be tweaked, or seriously changed (which they will need to be), go for it. The current values were generated via StarGen, which is a fine solar system generator, but one with a few issues, I think. At any rate, this is the planet in question, in a nutshell. Please let me know what you think, and how you might change it. Remember, the important thing is its biocompatibility 400 million years ago. Its current values are certainly open to change.

And finally, a quick shot of the planets in Celestia. I whipped up an add-on a couple of weeks ago, but it by no means is meant to be the final representation. In fact, today I plan on working on continental arrangements.

Thanks again!

...John...

_________________"Who are we? We find that we live on an insignificant planet of a humdrum star lost in a galaxy tucked away in some forgotten corner of a universe in which there are far more galaxies than people." Carl Sagan

Heya! thanks! Yeah, I've been working on it off and on for the past three years. The link to the site is on my profile here; a lot of items, however, are on paper and not online, but I'm striving to get things settled. The Time Line is probably the biggest update that I've had so far....

...John...

_________________"Who are we? We find that we live on an insignificant planet of a humdrum star lost in a galaxy tucked away in some forgotten corner of a universe in which there are far more galaxies than people." Carl Sagan

_________________"Who are we? We find that we live on an insignificant planet of a humdrum star lost in a galaxy tucked away in some forgotten corner of a universe in which there are far more galaxies than people." Carl Sagan

Um, I think if the planet is tidally locked always facing the star with one side, that the climate would be very contrasting on each half of the planet. The one facing the star would be superhot (especially since that its not an red dwarf but an orange one), and the other side would be quite cold.

So while you may have very hot tropical weather one one side, the other would probably be very cold.

If you wish to cut off the tidally locked thing, you may end up with a moderate to cooler climate.

That's the only thing I could find with the so far mentioned things. Other than that everything else seems fine to me.

A disparate climate on the two halves of the planet is not neccessarily going to be true. Assuming a thick enough atmosphere, as well as globally circulating oceans, heat transfer from the day to the night side could well be very efficient. Studies at the Ame's Research Center, for instance, have shown that a planet need only about 10% (or 100mb) of Earth's atmosphere for a heat transfer to be efficient enough to preserve habitability.

There are, of course, many other factors to consider, as well as the fact that we really do not know enough at this point to say whether such a world would be habitable or not. Based on my research, and discussions on the ArcBuilder and Orion Arm's mailing lists, I'm satisfied that such a world remains, at least for the time being, theoretically possible.

_________________"Who are we? We find that we live on an insignificant planet of a humdrum star lost in a galaxy tucked away in some forgotten corner of a universe in which there are far more galaxies than people." Carl Sagan